1. Field of the Invention
This invention relates to an electrical power distribution apparatus for an motor vehicle.
2. Description of the Prior Art
A power distribution apparatus for a motor vehicle controls distribution of a power to respective electric loads in the motor vehicle. Japanese patent application provisional publication No. 2000-23380 discloses a power distribution apparatus for a motor vehicle which selectively distributes a power from a power supply to a plurality of power supply terminals. When there is an error at a portion downstream from the power supply terminal, the power supply terminal cuts off the power to the corresponding electric load, and when there is an error at a portion upstream from the power supply terminal, the power distributor controls supplying the power to all electric loads.
In this system, if there is an error upstream from respective power supply terminals, the power is cut off to all electric loads to secure the safety in the circuit. If there is an error at one electric load, the power supply terminal supplying the power to the electric load cuts off the power. This enables the power distribution apparatus to maintain supplying the power to other electric loads.
However, if an error in the power supplying side is detected, supplying the power is stopped to all electric loads, so that the motor vehicle cannot travel no longer though there is a possibility to run because there is a power left in a battery.
The aim of the present invention is to provide a superior power distribution apparatus.
According to the present invention, a first aspect of the present invention provides a power distribution apparatus for a motor vehicle having a plurality of electric loads, a power supply for supplying a power to said electric loads, and distribution control means for independently controlling distribution of said power to said electric loads, said distribution control means further including: storing means for storing priorities of said electric loads for classifying said electric loads into a plurality of groups; detection means for detecting an error in a power feeding system including said power supply and said distribution control means and detecting a condition that it is possible to partially distribute said power to said electric loads in the presence of said error; and control means for distributing said power to a portion of said groups of said electric loads having said priority which is relatively high and cutting off said power to remains of said groups of said electric loads having said priority which is relatively low when said detection means detects said condition.
According to the present invention, a second aspect of the present invention provides a power distribution apparatus based on the first aspect, wherein said storing means further stores class data for classifying said electric loads into an essential group and a non-essential group, said detection means further detects, in the presence of said error, a second condition that said error will make it impossible to run said motor vehicle and a third condition that said error allows said motor vehicle to run, and said control means cuts off said power to at least said essential group of said electric loads on the basis of said class data when said detection means detects said second condition and distributes said power to said essential group of said electric loads and cuts off said power to at least a portion of said non-essential group of electric loads on the basis of said class data when said detection means detects said third condition.
According to the present invention, a third aspect of the present invention provides a power distribution apparatus based on the second aspect, wherein said detection means further detects a present ability of feeding said power from said power feeding system, and said third condition is detected by detecting whether a total of powers required by said electric loads exceeds said present ability of said power.
According to the present invention, a fourth aspect of the present invention provides a power distribution apparatus based on the first aspect, further comprising: second detection means for detecting whether there is an electric load error in said electric loads and detecting said priority of said electric load having said electric load error; and second control means for cutting off said power to at least one of said groups of said electric loads having a high priority when said detected priority is higher than a reference and distributing said power to said groups of said electric loads having high priorities and cutting off said power to said detected electric load when said second detection means detects said electric load error and said detected priority is not higher than said reference.
According to the present invention, a fifth aspect of the present invention provides a power distribution apparatus based on the second aspect, wherein, at start up of said motor vehicle, said detection means detects said error and, in the presence of said error, detects said second condition and said third condition, and said control means cuts off said power to at least said essential group of said electric loads and alarms the operator on the basis of said class data when said detection means detects said second condition and distributes said power to said essential group of said electric loads and cuts off said power to at least a portion of said non-essential group of electric loads and alarms the operator on the basis of said class data when said detection means detects said third condition.
According to the present invention, a sixth aspect of the present invention provides a power distribution apparatus for a motor vehicle having a plurality of electric loads, a power supply for supplying a power to said electric loads, and distribution control means for independently controlling distribution of said power to said electric loads, said distribution control means further including: storing means for storing priorities of said electric loads for classifying said electric loads into a plurality of groups; detection means for detecting whether there is an error in said electric loads and, in the presence of said error, detecting said priority of said electric load having said error; and control means for cutting off said power to at least one of said groups of said electric loads having said priority higher than a reference when said detected priority is higher than said reference and distributing said power to said groups of said electric loads having said priorities higher than said reference and cutting off said power to said detected electric load when said detection means detects said error and said detected priority is not higher than said reference.
According to the present invention, a seventh aspect of the present invention provides a power distribution apparatus based on the sixth aspect, wherein said storing means stores class data for classifying said electric loads into an essential group and a non-essential group, said detection means further detects, in the presence of said error, whether said electric load having said error belongs to said essential group or non-essential group on the basis of said class data, and said control means cuts off said power to at least all of said electric loads in said essential group when said electric load having said error belongs to said essential group and cuts off said power to said electric load having said error when said electric load having said error belongs to said non-essential group.
According to the present invention, an eighth aspect of the present invention provides a power distribution apparatus based on the sixth aspect, wherein said control means further cuts off said power to one of said electric loads having said priority which is lower than said detected priority and having relation data indicating a relation with said detected electric load when said detected priority is not higher than said reference.
According to the present invention, a ninth aspect of the present invention provides a power distribution apparatus based on the sixth aspect, further comprising: second detection means for detecting a power feeding error in a power feeding system including said power supply and said distribution control means, and detecting a condition that it is possible to partially distribute said power to said electric loads in the presence of said power feeding error; and second control means for distributing said power to a portion of said groups of said electric loads having a higher priority and cutting off said power to remains of said groups of said electric loads having a lower priority when said second detection means detects said condition.
According to the present invention, a tenth aspect of the present invention provides a power distribution apparatus based on the seventh aspect, wherein, at start up of said motor vehicle, said detection means further detects, in the presence of said error, whether one of said electric loads having said error belongs to said essential group or non-essential group, and said control means cuts off said power to at least all of said electric loads in said essential group and alarms the operator on the basis of said class data when said electric load having said error belonging to said essential group and cuts off said power to said electric load having said error and alarms the operator when said electric load having said error belongs to said non-essential group.
According to the present invention, an eleventh aspect of the present invention provides a power distribution apparatus for a motor vehicle having a plurality of electric loads, a power supply for supplying a power to said electric loads, and distribution control means for independently controlling distribution of said power to said electric loads, said distribution control means further including: storing means for storing priorities of said electric loads for classifying said electric loads into a plurality of groups; first detection means for detecting an error in a power feeding system including said power supply and said distribution control means, and detecting a condition that it is possible to partially distribute said power to said electric loads in the presence of said error; second detection means for detecting a degree of said error; and control means for successively distributing said power to one of said groups of said electric loads in order of said priority on the basis of said detected degree.